FIG. 1 is a cross-sectional view of a conventional rotating drum device. In FIG. 1, a reference numeral 1 designates a rotary shaft, a numeral 2 designates a fixed lower drum, a numeral 3 designates a rotating upper drum, a numeral 4 designates a head table detachably connected to the upper drum 3 by means of screws, a numeral 5 designates a magnetic head firmly connected to an end of the head table 4, a numeral 6 designates bearings placed between the rotary shaft 1 and the lower drum 2 to allow relative rotation of the lower drum 2 with respect to the rotary shaft 1, a numeral 7 designates an upper transmitter capable of rotating along with the upper drum 3, a numeral 9 designates a base block firmly attached to the rotary shaft 1 to support the upper drum 3, and a numeral 13 designates a magnetic tape.
The magnetic head 5 is placed at a fixed position with reference to the upper drum 3 and has its end slightly projecting from the outer periphery of the upper drum 3 which is rotated at a constant high speed. The magnetic tape 13 is obliquely wrapped around the outer circumferential surfaces of the upper and lower drums 3, 2 so as to travel on the surfaces at a predetermined speed, whereby the magnetic head 5 records or reproduces electromagnetically signals of images or sounds by the contact to the magnetic tape 13.
The upper transmitter 7 is attached to the base block 9 and rotates along with the base block 9. The magnetic head 5 is electrically connected to the upper transmitter 7 via a first connecting part 10, a wiring plate 11, and a second connecting part 12. A lower transmitter 8 faces the upper transmitter 7 with a minute space. The upper and lower transmitters 7, 8 are magnetically coupled for mutual transmission of signals. The lower transmitter 8 is connected to a signal processing unit (not shown) as an exterior device.
When the magnetic tape 13 travels on the outer circumferential surfaces of the upper and lower drums 3, 2 while the magnetic head 5 is rotated, the magnetic head 5 obliquely traverses on the magnetic tape 13. Lines which obliquely traverse the magnetic tape 13 are parallel with each other. FIG. 2 is a diagram showing a relation of the tracks of the magnetic head 5 to the magnetic tape 13. In FIG. 2, a reference numeral 13a designates a track of the magnetic tape 13, a symbol V.sub.1 represents a normal feeding speed of the magnetic tape 13, a numeral 5a is a track of the magnetic head 5, and a symbol V.sub.0 represents a speed of rotation of the magnetic head 5. As is apparent from FIG. 2, the track 13a and the track 5a are crossed, whereby the track (the traversing line) which is drawn on the magnetic tape 13 by the magnetic head 5 assumes as indicated by a character A as shown in FIG. 2a.
When the speed of the magnetic tape 13 is increased from a feeding speed V.sub.1 to a speed V.sub.2 (for instance, when high speed searching is to be conducted), a relative track of the magnetic head 5 to the magnetic tape 13 is shown by a character B as shown in FIG. 2b.
The magnetic tape 13 used for a VTR is sometimes operated for reproduction at a speed which is different from the normal feeding speed V.sub.1 as operated at the recording operation. For instance, the magnetic tape 13 is operated under various conditions such as "stop", "low", "high speed searching for reproduction" and so on. In this case, the relative track of the magnetic head 5 to the magnetic tape 13 is out of the relative track A in the normal operation as shown in FIG. 2a. For instance, the relative track during the high speed searching for reproduction assumes the relative track B as shown in FIG. 2b. Namely, the magnetic head 5 does not correctly trace the relative track A, (i.e. a track for recording at the normal feeding speed), and becomes out of the relative track A. Therefore, the intensity of signals picked up by the magnetic head 5 becomes low and noises are produced, whereby it is difficult to obtain clear reproduced images.